CHEMICAL PROCESS DIAGRAM

CHEMICAL PROCESS

DIAGRAM

SCOPE:

Students will be able to know:-

 Type of chemical process diagram - Block Flow Diagram (BFD)

- Process Flow Diagram (PFD)

- Piping and Instrumentation Diagram (P&ID)

 How to read and draw BFD, PFD and P&ID

 Process equipments symbol and numbering

Chemical Process Diagram

3 Levels of Diagram

-Block Flow Diagram (BFD) -Process Flow Diagram (PFD)

-Piping and Instrumentation Diagram (P&ID)

Chemical Process Diagram

BLOCK FLOW DIAGRAM (BFD)

The Block Flow Diagram (BFD)

Block Flow Diagram (BFD)

BFD shows overall processing picture of a chemical complex:

-Flow of raw materials and products may be included on a BFD

-BFD is a superficial view of facility – ChE information is missing

The Block Flow Diagram (BFD)

Reactor Gas Separator Toluene, C₇H₈

10,000 kg/hr

Hydrogen H₂ 820 kg/hr

Mixed Liquid

75% Conversion of Toluene

Mixed Gas 2610 kg/hr

Benzene, C₆H₆ 8,210 kg/hr

Reaction : C₇H₈ + H₂ C₆H₆ + CH₄

Figure 1.1: Block Flow Diagram for the Production of Benzene

C₆H₆ CH₄ C₇H₈

Example 1:

The Block Flow Diagram (BFD)

EXAMPLE 2

Production of Ethane from Ethanol

Ethanol is feed to continuous reactor with presence of Acid Sulphuric catalyzer to produce ethylene. Distillation process then will be applied to separate ethylene-H2O mixture. Ethylene as a top product is then condensate with condenser to perform liquid ethylene. Hydrogenation of ethylene applies in another reactor with presence of Nickel catalyzer to produce ethane as a final product. Develop BFD for these processes.

Reactor 1 Ethanol,

C₂H₅OH

H₂SO₄ Reactor 2

Distillation column

Ethylene, CH₂CH_{2 (g)}

Ethane, CH₃CH₃

CH₃CH₂OH _H2SO4 CH₂=CH₂ + H₂O CH₂=CH₂ + H_{2 Ni} CH₃CH₃

Ni Hydrogen, H₂ Cold water in

Hot water out

H₂O CH₂CH₂

H₂O

Ethylene liq. CH₂CH_{2 (l)}

Exercise 1:

Ammonia-air mixture is feed to the bottom stream of an absorber with flow rate of 10L/min. Water then feed to the upper stream of the same absorber with desired flow rate of 5L/min. There are two outputs from the absorber where upper stream is insoluble NH₃ and bottom stream is NH₃-Water mixture. This NH₃-water mixture then feed up to a batch distillation column. The column produces ammonia gas as a top product which this product then will be condensate with a condenser to produce liquid ammonia.

Develop Block Flow Diagram (BFD) for this process.

The Block Flow Diagram (BFD)

Answer 1

Absorber Batch

Distillation Water 5 L/min

Ammonia-air mixture 10 L/min

Insoluble ammonia

Ammonia-water mixture

Ammonia gas

Cold water in

Hot water out

Ammonia liquid Condenser

The Block Flow Diagram (BFD)

Exercise 2:

Ethanol-water mixture is feed to a batch distillation column. This distillation process will produce ethanol vapour at the top product which then condensate to

produce liquid ethanol which then collected into a distillate product tank. This liquid ethanol and an acetic acid liquid from a acid feed tank are then feed to a reactor. An

exothermic chemical reaction will producing ethyl acetate (a type of ester). Draw BFD for this chemical process.

The Block Flow Diagram (BFD)

Answer 2

Batch distillation

Reactor Distillate

product tank

Acid feed tank Ethanol-water

mixture

Cold water in

Hot water out

Ethanol

liq. Ethyl

acetate Condenser

The Block Flow Diagram (BFD)

PROCESS FLOW DIAGRAM

The Process Flow Diagram (PFD)

SCOPE:

Students will be able to know:-

 Process Unit symbology

 How to read and draw PFD

 Process equipments symbol and numbering

The Process Flow Diagram (PFD)

Process Flow Diagram (PFD)

PFD shows all process engineering information:

-The topology of the process – showing the connectivity of all the streams and the equipment.

-Use appropriate conventions – consistency is important in communication of process information.

The Process Flow Diagram (PFD)

PFD will contains the following information:-

- All major pieces of equipment (descriptive name, unique equipment no.), pumps and valves.

- All the utility streams supplied to major equipments such as steam lines, compressed air lines, electricity, etc.

- All process flow streams: identification by a number, process condition, chemical composition.

- Basic control loops: showing the control strategy used to operate the process under normal operations.

The Process Flow Diagram (PFD)

The Process Flow Diagram (PFD)

PFD will contains the following information:-

- All major pieces of equipment (descriptive name, unique equipment no.), pumps and valves.

- All the utility streams supplied to major equipments such as steam lines, compressed air lines, electricity, etc.

The Process Flow Diagram (PFD)

Process Unit Symbology

Symbol Description

Heat exchanger

H₂O Water cooler

S Steam heater

Cooling coil

The Process Flow Diagram (PFD)

Process Unit Symbology

Symbol Description

Heater coil

Centrifugal pump

Turbine type compressor

Pressure gauge

The Process Flow Diagram (PFD)

Process Unit Symbology

Symbol Name

Stripper

Absorber

A separator unit used commonly to liquid mixture into gas phase

Description

A separator unit used commonly to extract mixture gas into liquid phase

The Process Flow Diagram (PFD)

Process Unit Symbology

Symbol Name

Distillation column

Liquid mixer

A separator unit used commonly to crack liquid contains miscellaneous component fractions.

Description

A process unit that used to mix several components of liquid.

or

The Process Flow Diagram (PFD)

Process Unit Symbology

Symbol Name

Reaction chamber

Horizontal tank or cylinder

A process unit where chemical process reaction occurs

Description

A unit to store liquid or gas.

The Process Flow Diagram (PFD)

Process Unit Symbology

Symbol Name

Boiler

Centrifuge

A unit for heating.

Description

A separator unit that to physically separated liquid mixture. (exp: oil-liquid)

The Process Flow Diagram (PFD)

Valve Symbology

Symbol Name

Gate Valve

Check Valve

The Process Flow Diagram (PFD)

Globe Valve

Ball Valve

Butterfly Valve

Valve Symbology

Symbol Name

Relief Valve

Angle Valve

The Process Flow Diagram (PFD)

Needle Valve

3-Way Valve

Butterfly Valve

EXAMPLE 3

Production of Ethane from Ethanol

Ethanol is feed to continuous reactor with presence of Acid Sulphuric catalyzer to produce ethylene. Distillation process then will be applied to separate ethylene-H2O mixture. Ethylene as a top product is then condensate with condenser to perform liquid ethylene. Hydrogenation of ethylene applies in another reactor with presence of Nickel catalyzer to produce ethane as a final product. Develop PFD for these processes.

CH₃CH₂OH ^H2SO4 CH₂=CH₂ + H₂O CH₂=CH₂ + H_{2 Ni} CH₃CH₃

T-100

Distillation Column

Ethanol H₂SO₄

Ethylene Ethylene liq.

Ethane Ni

Hydrogen

Cold water in

Hot water out

H₂O

R-100 Reactor

E-100 Condenser

R-101 Reactor

R-100

T-100

E-100

R-101 P-100

Pump

P-101 Pump

P-100

P-101 V-100 V-101 V-102

V-103

V-104

V-105

V-106

V-107 CV-101 CV-100

Exercise 3:

Ammonia-air mixture is feed to the bottom stream of an absorber with flow rate of 10L/min. Water then feed to the upper stream of the same absorber with desired flow rate of 5L/min. There are two outputs from the absorber where upper stream is insoluble NH₃ and bottom stream is NH₃-Water mixture. This NH₃-water mixture then feed up to a batch distillation column. The column produces ammonia gas as a top product which this product then will be condensate with a condenser to produce liquid ammonia.

Develop Process Flow Diagram (PFD) for this process.

The Process Flow Diagram (PFD)

Answer 3

Water 5 L/min

Ammonia-air mixture 10 L/min

Insoluble ammonia gas

Ammonia-water mixture

Ammonia gas

Cold water in

Hot water out

Ammonia liquid

The Process Flow Diagram (PFD)

T-100

Absorber Column

T-101

Batch Distillation Column

E-100 Condenser

Process Equipment General Format XX-YZZ A/B

  XX are the identification letters for the equipment classification

  C - Compressor or Turbine

  E - Heat Exchanger

  H - Fired Heater

  P - Pump

  R - Reactor

  T - Tower

  TK - Storage Tank

  V - Vessel

  Y - designates an area within the plant

  ZZ - are the number designation for each item in an equipment class   A/B - identifies parallel units or backup units not shown on a PFD Supplemental Information Additional description of equipment given on top of PFD

The Process Flow Diagram (PFD)

Process Unit Tagging and Numbering

The Process Flow Diagram (PFD)

Area No. 1

Area No. 2

Area No. 3

Y Letter

The Process Flow Diagram (PFD)

A/B Letter

Example

Ethanol H₂SO₄

Ethylene Ethylene liq.

Ethane Ni

Hydrogen Cold

water in

Hot water out

H₂O

P-100 A/B

In PFD

Ethylene Ethylene liq.

Ethane Ni

Hydrogen Cold

water in

Hot water out

H₂O P-100 A

P-100 B

In real plant, it means like above

PFD will contains the following information:-

- All process flow streams: identification by a number, process condition, chemical composition.

The Process Flow Diagram (PFD)

Stream Numbering and Drawing

- Number streams from left to right as much as possible.

- Horizontal lines are dominant.

Yes No No

The Process Flow Diagram (PFD)

EXAMPLE 4

T-100

Distillation Column

Ethanol H₂SO₄

Ethylene Ethylene liq.

Ethane Ni

Hydrogen Cold water in

Hot water out

H₂O

R-100 Reactor

E-100 Condenser

R-101 Reactor

R-100

T-100

E-100

R-101 P-100

Pump

P-101 Pump

1

2 3

4

5

6

7

8

9

10

V-100

V-101 V-102

V-103

V-104

V-105

V-106

V-107 CV-100

CV-101

P-100

P-101

Stream Information

The Process Flow Diagram (PFD) (cont..)

-Since diagrams are small not much stream information can be included.

-Include important data – around reactors and towers, etc.

Flags are used

Full stream data,

1

2

3

4

5

6 7

8

11

9

10

12

13

600 24

24

300

Stream Information - Flag

The Process Flow Diagram (PFD) (cont..)

600 Temperature

24 Pressure

10.3 Mass Flowrate

108 Molar Flowrate Gas Flowrate Liquid Flowrate

EXAMPLE 5

25 28

35 32.2

35 31.0

38 20

T-100

Distillation Column

Ethanol H₂SO₄

Ethylene Ethylene liq.

Ethane Ni

Hydrogen Cold water in

Hot water out

H₂O

R-100 Reactor

E-100 Condenser

R-101 Reactor

R-100

T-100

E-100

R-101 P-100

Pump

P-101 Pump

1

2 3

4

5

6

7

8

9

10

V-100

V-101 V-102

V-103

V-104

V-105

V-106

V-107 CV-100

CV-101

P-100

P-101

Stream

Number 1 2 3 4 5 6 7 8 9 10

Temperature

(oC) 25.0 35.0 35.0 35.0 35.0 60.3 41 38 54.0 45.1

Pressure (psi) 28 32.2 31.0 31.0 30.2 45.1 31.3 24.0 39.0 2.6

Vapor fraction Mass flow

(tonne/hr) 10.3 13.3 0.82 20.5 6.41 20.5 0.36 9.2 20.9 11.6

Mole flow

(kmol/hr) 108 114.2 301.0 1204.0 758.8 1204.4 42.6 1100.8 142.2 244.0

Stream Information - Full stream data,

EXAMPLE 6

Stream Number 1 2 3 4 5 6 7 8 9 10

Temperature (oC) 25.0 35.0 35.0 35.0 35.0 60.3 41 38 54 45.1

Pressure (psi) 28 32.2 31.0 31.0 30.2 45.1 31.3 24.0 39 2.6

Vapor fraction

Mass flow (tonne/hr) 10.3 13.3 0.82 20.5 6.41 20.5 0.36 9.2 20.9 11.6

Mole flow (kmol/hr) 108 114.2 301.0 1204.0 758.8 1204.4 42.6 1100.8 142.2 244.0 25

28

35 32.2

35 31.0

38

20

T-100

Distillation Column

Ethanol H₂SO₄

Ethylene Ethylene liq.

Ethane Ni

Hydrogen Cold water in

Hot water out

H₂O

R-100 Reactor

E-100 Condenser

R-101 Reactor

R-100

T-100

E-100

R-101 P-100

Pump

P-101 Pump

1

2 3

4

5

6

7

8

9

10

V-101 V-102

V-103 CV-100

V-100

V-104

V-105

V-106

V-107 CV-101

P-100

P-101

PFD will contains the following information:-

- Basic control loops: showing the control strategy used to operate the process under normal operations.

The Process Flow Diagram (PFD)

EXAMPLE 7

Stream Number 1 2 3 4 5 6 7 8 9 10

Temperature (oC) 25.0 35.0 35.0 35.0 35.0 60.3 41 38 54 45.1

Pressure (psi) 28 32.2 31.0 31.0 30.2 45.1 31.3 24.0 39 2.6

Vapor fraction

Mass flow (tonne/hr) 10.3 13.3 0.82 20.5 6.41 20.5 0.36 9.2 20.9 11.6

Mole flow (kmol/hr) 108 114.2 301.0 1204.0 758.8 1204.4 42.6 1100.8 142.2 244.0

T-100

Distillation Column R-100

Reactor

E-100 Condenser

R-101 Reactor P-100

Pump

P-101 Pump

25 28

35 32.2

31.035

38 Ethanol 20

H₂SO₄

Ethylene Ethylene liq.

Ethane Ni

Hydrogen Cold water in

Hot water out

H₂O

R-100

T-100

E-100

R-101

1

2 3

4

5

6

7

8

9

10 LIC

LIC

V-100

V-101

V-103

V-102 CV-100

V-104

V-105

V-106 CV-101

V-107

P-100

P-101

QUESTIONS?